This dynamic would have worked if it was a jdrama but, alas.
well you could say that and I do agree with nuanced acting by Japanese actors which is the primary reason why most jdramas gets off the radar and the other reason would be unavailability of international OTT apart from that it can't be said that all the contents coming from Japanese creators are useless.
The writer of this drama is unexpected, looking at their page they mainly write mystery-thrillers lol yet here…
They can pull off a mystery element in the middle if they want to connect a subtle mystery regarding the motel. Like you said, some previously aired Rom/melodramas had a thriller/mystery subplots in the middle of the story.
so WKC2 should be coming in later months